Friction shock-absorbing mechanism



March 26, 1929. ,1. F. OCONNOR 1,706,463

FRICTION SHOCK ABSORBING MECHANISM 1 Filed Aug. 26 192'? 2 Sheets-Sheet l w I 110M) March 26, 1929. F, O'CONNOR FRICTION snocx .ussomame mwcrumrsu 2 Sheets-Sheet 2 Filed Aug. 26, 1927 120mm ohn/1.

Wzi'mzii Patented Mar. 26, 1929.

UNITED; STATES JQHN F. OCONNOR, 0E cH'rcAeo, ILLINois, ASSIGNOR TO w. n; MINER, mo, 0E CHI- CAGO, ILLINOIS, A CORPORATION OF DELAWARE.

ATENT F 4 FRICTION SHOCK-ABSORBING MECHANISM.

Apmm mn filedlAugust as, 1927. Serial No. 215,567.

This invention relates to improvements in friction shock absorbing mechanisms. One object of the invention is to provide a friction shock absorbing mechanism, especially adapted for railway draft riggings,

having graduated action during the compression stroke, including a plurality of relatively movable friction plates, wherein all of the plates are movableqas'a unit during a predetermined portion of the compression stroke to effect relatively light resistance,followed by a relative movement of the plates to augment the resistance offered, certain of said plates being engaged by abutment means to arrest their movement and permit movement of the remaining plates relatively thereto.

Another object of the invention is to provide a friction shock absorbing mechanism of the intercalated plate type, including a friction shell and a plurality of groups of plates, together with spreading means comprising a wedge member, wherein certain members of each group of platesare anchored to the friction shell to limit outward movement thereof and in turn co-operate with abutment means on the wedge member ,to anchor the latter to the shell and limit its outward movement.

Other objects and advantages of the invention will more fully and clearly appear from the description and :claims hereinafter following. p

In the drawings, forming a part ofthis specification, Figure 1 is a horizontal longitudinal sectional View of a portion of trailway draft rigging, showing my improve" ments in connection therewith. Figure 2 is a front end elevational view of my improved shock absorbing mechanism proper. Figure 3 is a transverse, vertical sectional view corresponding substantially to the line 33 of Figure 1. And Figures 4: and-5 are detailed perspective views, respectively, of a liner and a friction plate employed in connection with my improved shock absorbing mechanism.

In said drawings, 1O-10 indicate channel shaped center or draft sills of a railway car under-frame, to the innersides of which are secured front stop lugs 11-11 and rear stop lugs. 12-12. The inner end portionof the drawbar is designated'by 13, to which is operatively connected a yoke 14 of well known form. The shock absorbing .mechanism proper, and a-front main follower 15, are disposedwithin the yoke and the yoke in turn is operatively supported by a detachable saddle plate 16, secured to the draft sills.

My improved shock absorbing mechanism pro-per, as shown, comprises-broadly, a combined friction shell and spring cage A; a main wedge B; two friction shoes O and D; two groups of friction plates each comprising one set of plates E and another set of plates F; a main spring resistance G; an additional spring resistance H; a spring follower J; a spring follower cap K; and a pair of liners M.M.

The combined friction shell and spring cage A is in the form of a substantially rectangular box-like casting having spaced hori zontally disposed top and bottom walls 1717, spaced vertically disposed side walls 1 8 18, and a transverse vertical rear end wall 19. The end wall 19 co-operates with the, stop lugs 12 inthe manner of the usual rear follower. walls 18 are inwardly thickened as indicated at 20, and are cut away as indicated at 21 to provide seats to receiveretaining means on the liners M to hold the latter against movement longitudinally of the cage A. Inwardly of the thickened port-ions 20,'each side wall 18 is also provided, withv a vertically disposed, rela-t-lyely heavy abutment rib 22 which acts as a limiting stop for certain of the friction plates, as hereinafter more clearly pointed out.

The liners M are in the form of substantlally rectangular plates, and as most clearly shown in Figures 1 and. 4, have the rearend portions thereof outwardly offset as indicated The offset portions 23 of the liners are adapted to fit within the. seats 21 of the At the forward end the side side walls .18 and thus anchor the liners to faces 25 and 26. As most clearly shown in Figure 1,, the wedge face '25 is disposed atav relatively blunt angle with respect to the longitudinal axis ofthe mechanism, while the wedgeface 26 is disposed at a relatively keen angle with respect to said axis. Inwardly of the front end thereof, the wedge block B.

is provided with vertically disposed laterally projecting abutment ribs 27 27 whieh cooperate with certain of the friction plates, as hereinafter pointed out, to limit outward m n o h W d a d o d the parts of the mechanism assembled.

The friction shoes C and D are two in number and are dis JOSGCl at o. .iosite sidesof the wedge block B, the shoe C co-operating with the keen wedge face of the block and the shoe D co-operating with the blunt wedge face thereof." The shoes C and D are of substantially the same design except as hereinafter pointed out. Each shoe is provided with a longitudinally disposed flat friction surface 28 on the outer side thereof. On the inner side each'shoe carries a lateral enlargement 29 having the wedge face at the forward side thereof. The wedge face of the shoe D is indicated by 125, and the wedge face of the shoe 0 is indicated by126. The wedgejface 125 is adapted to co-operate with the blunt wedge face 25 of the wedge block B while the wedge face 126 of the shoe C is adapted to co-operate with the keen wedge face 26 of said bloclr. The inner ends of the enlargements 29 of the shoes present flat'transverse abutment faces cooperating with the spring follower c ap The friction plates E and F comprise two groups at opposite sides of the mechanism, interposed between the friction shoes and the liners M. Each group of plates comprises a set of two plates E and a set of two plates F. As clearly shown in Figures 1, 2 and 3, the plates E and F of each group are alternated and one of the plates E is disposed outermost and co-operates with the friction surface of the liner M at the corresponding side of the mechanism. The plate last referred to is most clearly illustrated in Figure 5. This plate comprises a main body portion havinga relatively wide lateral flange 30 at the forward end thereof and a relatively narrow rib-like flange 3.1 at the rear end thereof. The flange 31 projects laterally outwardly, as most clearly illustrated in Figure 1, and engages in back of a shoulder 32 formed by the offset portion of the liner M, thus limiting outward movement of the plate; The remaining plate of the set E is interposed between the two plates of the set F and has a laterally inwardly projecting flange 33 at the forward end thereof bearing on the inner side of the flange 30 of the outermost plate of the set E. It will h e-evident that the inner plates of the two sets E are thus limited in their outward movement by engagement with theflanges 30,. As most clearly shown in Figure 1, the flanges of the inner plates of the sets E over-hang'the flanges 27 on the wedge block B and thus limit outward movement of the wedge block. The two plates F of each set are provided with lateral flanges 34 at the rear ends thereof,the flange 34 of the innermost plate of each set bearing on the flange 34 of the remaining plate of said set and being also adapted to engage the corresponding stop rib 22 at the same side of the cage to positiv y l mit nwa d m v m t of t -two Pl e F of c gr an.

The spring resistance H comprises a relatively light coil having its opposite ends bearing respectively onthe end wall 19 of the cage and on the spring follower cap K which, as hereinbefore pointed out, bears on the friction shoes C and D. The outer coil G of the spring resistance is heavier than the inner coil and has the rear end thereof hearing on the end wall 19 of the cage. The front end of the coil Gr bears on the spring follower which, is interposed between the spring and the flanges 34' of the innermost friction plates. The spring follower J is pro vided with an opening through which the inner coil ofthe spring H passes freely.

When the mechanism has been assembled, the parts are so proportioned that the main spring resistance elements G and H are under initial compression, thereby holding all of the parts of the mechanism in their outermost position and also compensatin for wear of the various friction and wedge races.

In assembling the mechanism, the main sprin resistance elements G and H, together with the spring followers J and K, are inserted within the spring cage. The friction system comprising the wedge block B, the friction shoes C and D and the friction plates E and F, are next assembled as a unit and inserted within the cage. The entire friction system'as assembledis then compressed sotionsthereof will register with the seats 21.

of the side walls of'the cage. dVhen the parts have been thus alined, the entire friction system is, permited to expand, thus forcing the parts laterally outwardly and seating the retaining means on the liners in the seats of the cage;

The operation of my improved shock absorbing mechanism, assuming a compression stroke, is as vfollows: The'main follower 15 and the cage A,will be moved relatively toward each other, thereby carryingthe wedge block B inwardly of the cage and wed ging the shoes C and D laterally'outwardly; It will be evident that during this actionvinward movement of the shoes C and D is re sisted by the central coil H of the spring re sistance. Inasmuch as the wedge block B and the shoes C are provided with co-operating keen wedge faces, a heavy wedging action will beset up. During this wedging action'the co-oper'ating wedge faces of the ing during release to preventsticking of the parts. As the wcc-ge block is moved inwardly with respect to the cage, the shoes will be carried inwardly in unison therewith and due to the friction existing between the shoes and between the plates of each group, the plates will be carried inwardly of the casing along the friction surfaces of the liners M. Due to the friction existing between the liners and the outermost friction plates, there is a tendency to retard movement of these plates, but inasmuch as the plates are engaged by the main follower after slight movement of the latter, the same will be positively forced inwardly of the mechanism. It will he noted that a slight clearance is provided between the outer ends of the plates E and the main follower 15, thus assuring setting up of the wedging action between the wedge block and the friction shoes before the plates are actu ally engaged by the follower. Inward movc ment of the friction plates E and F substantially in unison with the friction shoes and wedge block B will continue until the flanges Selon the plates F come into engagement with the stop ribs 22, whereupon movement of the plates F will be positively arrested and the plates E will be forced to slide on the friction surfaces of the plates F, thereby greatly increasing the frictional resistance produced during the latter part of the compression stroke. The described action will continue either until the actuating force is reduced or the follower engages the front end of the spring cage A, whereupon the actuating force will be transmitted directly through the cage, the latter acting as a solid column load transmitting member to prevent undue compression of the main spring resistance.

During release, upon the actuating force being reduced, the expansive action of the spring resistance elements G and II will force the parts outwardly, the friction shoes being forced outwardly by the inner spring H and the friction plates being forced outwardly by the outer spring G. Outward movement of the plates F will be finally limited'by engagen'ient with the inner ends of the liners M,

most clearly shown in Figure 1, the flanges 34 of the plates F being of such a width as to overhang the rear ends of the liners.

Upon movement of the plates F being arrest-- ed, the plates E will be carried outwardly the flanges 27 of the wedge block B which.

ei igage with the flanges of the plates E. Outward movement of the outermost plate E of each set is limited by engagement. of the flange 31 thereof with the offset shoulder portion 82 of the corresponding liner. Movement of the innermost plate E of each set is positively limited by engagement with the flange of the outer plate of said set, and the lange 33 limits the outer movement of the wedge block B, thus maintaining the overall length of the mechanism. It is also pointed out that release of the mechanism is assured by providing the co-operating blunt tion shell having opposed interior friction surfaces; of a'group of friction plates at each side of the shell, each group including a set of plates having a predetermined amount of movement inwardly of the shell and a second set of plates having frictional engagementwith said first "named set; c'o-operating means on the shell and the first set of plates for positively arresting movement of the.

plates after a predetermined compression of the mechanism; wedge pressure transmitting means; friction shoes interposed between said wedge pressure transmitting means and friction plates; and spring resistance means including a member opposing inward movement of the shoes and a member opposing inward movement of said plates.

2. In. a friction shock absorbing mechanism, the combination with a rectangular friction shell having opposed interior friction surfaces on the opposite side walls thereof ;-of a group of friction plates at each side of the mechanism, each group including a set of plates having co-operating lateral flanges at the inner ends thereof, and a second set of plates having frictional engagement with the first set, said second set having (to-operating lateral flanges at the forward ends thereof; stop shoulders on the shell co-operating with the lateral flanges of the first set of plates to arrest inward movement of said setof plates after a predetermined compr ion of the mechanism; friction shoes interposed between said'groups of plates; wedge pressure transmitting means engaging said shoes; and a spring resistance, including an inner and outer coil, said inner coil opposing inward movement of the shoes and said outer coil opposing inward movement of said first set of plates of each group.

3. In a friction shock absorbing mechanism, the combination with a frictionshell; of a friction system co-operating with the shell, including relatively movable groups of plates at each side of the shell, friction shoes co-operating with the plates and a wedge block having wedging engagement with the shoes, certain of said plates of saidgroups having their outward movement limited by abutment means on the shell, said last named plates having means thereon for anchorin the wedgeblock to the shell;and spring r5. sistance means co-operating with said friction system. I 1

nism the combination with a friction shell;

of friction plates co-operating with the shell, certain of said plates having lateral projections at the outer ends thereof, said plates and the shell having cooperating abutment means thereon for limiting outward movement of said plates; friction shoes co-operating with the plates; a wedge block engaging the shoes, said wedge block having shoulders engaging the lateralprojections of the plates to anchor the wedge block to the shell and limit outward movement thereof; and spring resistance means within the shell opposing inward. movement of the plates and shoes.

5. In afriction shock absorbing mechanism, the combination with a casing having opposed side walls; of detachable liners anchored to the side walls; a wedge pressure transmitting block; friction shoes co-operat ing with the block; two groups of friction plates at opposite sides of the mechanism interposed between the shoes and liners, each group including two sets of alternated plates, the outermost plate of one set of each group having an abutment shoulder thereon engaging the abutment shoulder on the corresponding liner to limit outward movement of the plate, the said plate and another plate of said set having co-operating lateral projections V at the front ends thereof limiting outward movement of said last named plate, said wedge having abutment means thereon cooperating with the projection on said last named plate for anchoring the wedge to the casing and limiting outward movement of the wedge; and spring resistance means opposing ll'lOVGHlGHi) of said plates and shoes inwardly of the casing.

In witness that I claim the foregoing I have hereunto subscribed my name this 24th day of August, 19:27.

JOHN F. OCONNOR. V 

